code: def prepare_words_list(wanted_words):
      """Prepends common tokens to the custom word list.
  
      Args:
        wanted_words: List of strings containing the custom words.
  
      Returns:
        List with the standard silence and unknown tokens added.
      """
      return [SILENCE_LABEL, UNKNOWN_WORD_LABEL] + wanted_words
  
imports: import hashlib
  import math
  import os.path
  import random
  import re
  import sys
  import tarfile
  import numpy
  import urllib
  import tensorflow
  from tensorflow.python.ops import gen_audio_ops
  from tensorflow.python.ops import io_ops
  from tensorflow.python.platform import gfile
  from tensorflow.python.util import compat
label_desc: Use image node_id 1 for calling a global function with example usage: prepare_words_list(wanted_words) and returns: unknown